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UNITED STATES PATENT "OFFICE.

JULIUS FRIEDRICH FERDINAND FRANZ LowE, OF FRANKFORT-ON-THE- MAIN, GERMANY.

WHITE LEAD.

SPECIFICATION forming part of Letters Patent No.-417,434, dated December 17, 1889. Application filed August 17, 1887. Serial No. 247,148. (Specimens) Patented in France April 13, 1887, No. 182,852 in Germany April 13,1887, No. 42,307, No. 9,858 in Austria-Hungary December 17, Russia May 3, 1889,11'0. 5,205. I

To all whom it may concern:

Be it known that I, JULIUS FRIEDRICH FERDINAND FRANZ LoWE, doctor of philosophy, have invented new and useful Improvements in the Manufacture of White Lead, (for which there have been granted a patent in France, dated April 13, 1887, No. 182,852; in Austria-Hungary, dated December 17, 1887, No. 23,511 and No. 56,303, and December 20, 1888, No. 27,932; in England, dated June 27, 1887, No. 9,122, and July 6, 1888, No. 9,858; in Russia, dated May 3/15, 1889, No. 5,205, and in Germany, dated April 13, 1887, No. 42,307, and January 27, 1888, No. 45,259,) of which the following is specification.

,This invention relates to a speedy process for maufacturing white lead in two operations, whereby a product of constant and uniform chemical composition having properties equal to that made by the Dutch method is obtained.

OPERATION I.

Manufacture of carbonate of lead-I dissolve fifty parts, by Weight, of neutral acetate of lead (sugar of lead) or 43.6 parts of neutral lead nitrate in from two hundred and fifty to three hundred parts ofwater, and to this solution I add gradually by stirring twenty-three parts of solid sodium bicarbonate, (or 26.4 part solid potassium bicarbonate;) or I add a solution of eight parts of anhydrous soda ineight parts of Water, or ten parts of carbonate of potash in ten parts of water while stirring to either of the abovementioned lead solutions, and then add nine to ten parts solid bicarbonate of soda, (or twelve parts solid bicarbonate of potash.) The lead-carbonate precipitate which forms is allowed to settle and the supernatant liquid is decanted off. The precipitate is then stirred up with about an equal qantity of water and allowed to settle again and the second liquid decanted. When sugar of lead is employed, the decanted-and collected soand January 27, 1888,No. 45,259; in England June 27, 1887, No. 9,122, and July 6,1888, 1887,1111. 23,511 and No. 56.303, and December 20,1888,N0. 27,932, and in lution contains acetate of soda. If lead nitrate be employed, it will contain nitrate of soda, (Chili saltpeter,) obtainable as a by-product by evaporating.

OPERATION II.

Manufacture of a basic lead-salt solutionsuch as basic lead aoetateand the conversion ofno rmal lead carbonate into basic lead carbonate, (white Zead.)-I dissolve twenty-five parts of sugar of lead in from one hundred and twenty-five to one hundred and fifty parts water in a flask, and add thereto fifteen parts of good finely-ground litharge. I allow this to remain for from eight to ten hours at the ordinary tenlperture, but for a shorter period, if heated, stirring from time to time until all the litharge is dissolved, only a little white residue remaining at the bottom. I decant the liquid carefully from the residue, and add it while stirring to the normal carbonate of lead produced by Operation I. After thoroughly mixing the white lead thus formed is allowed to settle down, and after a little while the clear solution is decanted off, the white lead pressed well in the filterpress, and the expressed liquid'collected and added to the decanted portion. This collected solution contains the regenerated sugar of lead, and, after again adding to it fifteen parts of litharge, (Operation IL) is used again for converting a fresh quantity of normal carbonate of lead into basic carbonate of lead, (white lead.

The white lead made according to the above-described process has the following composition: Lead oxide 86.185

.11. $322.3 2218 loss bylgmtwn- Having thus described my invention and the manner of employing the same, what I claim, and wish to secureby Letters Patent ot the United States of America, is-

The process of making white lead, which consists in treating; a solution of the norto this specification in the presence of two Inal acetate or nitrate of lead with bicarbonsubscribing" witnesses.

Me of Potash and supiecfing the 1 JULIUS FRIEDRICH FERDINAND FRANZ LOWE. lnal lead carbonate thus obtained to the action 5 of a basic acetate of lead, substantially as set \Vitnesses:

forth. FRANZ WIRTH,

In testimony whereof I have signed my name JOSEPH PATRICK. 

